Process for the interconversion of two seperate crystal forms of a herbicidal pyridine sulfonamide

Abstract

This invention relates to the interconversion of separate crystal forms of (aminosulfonyl)pyridinecarboxamides. The compounds of this invention and their agriculturally suitable salts are useful as agricultural chemicals, and in particular, as herbicides which may be selective to corn.

What is claimed is: 
     
       1. A dry flowable preparation which comprises ##STR7## as the active ingredient prepared by hydrating ##STR8## or hydrating ##STR9## in the presence of heat. 
     
     
       2. An improved dry flowable herbicidal composition comprising 2[[(4,6-dimethoxypyrimidine-2-yl)aminocarbonyl]aminosulfonyl]-N,N-dimethyl-3-pyridinecarboxamide as an active ingredient and at least one of a surfactant and at least one diluent, wherein the improvement comprises use of the crystal lattice form of said active ingredient of Formula Ib ##STR10## having a water dispersibility of less than about 0.002. 
     
     
       3. An improved dry flowable herbicidal composition comprising 2[[(4,6-dimethoxypyrimidine-2-yl]aminocarbonyl]aminosulfonyl]-N,N-dimethyl-3-pyridinecarboxamide as an active ingredient and at least one of a surfactant and at least one diluent, wherein the improvement comprises use of the crystal lattice form of said active ingredient of Formula II ##STR11## having a water dispersibility of less than about 0.002. 
     
     
       4. An improved dry flowable herbicidal composition comprising 2[[(4,6-dimethoxypyrimidine-2-yl)aminocarbonyl]aminosulfonyl]-N,N-dimethyl-3-pyridinecarboxamide as an active ingredient and at least one of a surfactant and at least one diluent, wherein the improvement comprises use of the crystal lattice form of said active ingredient of a mixture of Formula Ib ##STR12## and Formula II ##STR13## having a water dispersibility of less than about 0.002. 
     
     
       5. A process for the preparation of an improved dry flowable herbicidal composition of claim 2, 3, or 4 comprising granulizing a compound of Formula Ib, II, or a mixture thereof, in the presence of water and at least one of a surfactant and at least one diluent.